【答案】：
an, on, too, 不填, comes, on, rides
【解析】：
1. "umbrella"以元音音素开头，用"an"；2. "在雨天"用"on a rainy day"；3. "住得太远"用"too far"；4. "去上学"是"go to school"，不加"the"；5. "here comes..."是倒装句，主语"the school bus"是单数，用"comes"；6. "在公交车上"用"on the school bus"；7. "Li Lin"是第三人称单数，"ride"用"rides"。
